CVE-2022-21159Public exploitNetwork attack vector

Service interruption via unchecked parser error

Published Apr 15, 2022 · Updated Apr 15, 2025

Infinite loop in libIEC61850 1.5.0 allows remote attackers to interrupt IEC 61850 server communications via malformed messages. parseNormalModeParameters fails to reject a -1 error returned by parsePresentationContextDefinitionList, so its outer buffer loop resumes from a negative offset. Repeated requests can strand every per-connection thread—100 by default—and prevent legitimate MMS connections without crashing the host.

CVSS severity7.5
High
EPSS probability1.82%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Infinite loop in libIEC61850 1.5.0 allows remote attackers to interrupt IEC 61850 server communications via malformed messages. parseNormalModeParameters fails to reject a -1 error returned by parsePresentationContextDefinitionList, so its outer buffer loop resumes from a negative offset. Repeated requests can strand every per-connection thread—100 by default—and prevent legitimate MMS connections without crashing the host.

The record

CVE
CVE-2022-21159
Published
Apr 15, 2022
Updated
Apr 15, 2025
Vendor
MZ Automation GmbH
Product
libIEC61850
Classifications
CWE-835, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MZ Automation GmbH · libIEC61850version=1.5.0

Published CVSS scores

7.5Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499.002Service Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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